$\begingroup$@Randal'Thor Pretty sure the same objection still applies though. There are a potentially infinite number of functions that could be represented by "+", or it might not even be a function but three somewhat-related sequences.$\endgroup$
– edderioferJul 10 '17 at 15:06

$\begingroup$i bet it has something to do with the powers of 2 (and/or 3)$\endgroup$
– MariusJul 10 '17 at 15:07

I observed that in the first equation $a * (b - 1)$ gives us $2 * 1 = 2$,
and in the second it gives us $4 * 7 = 28$,
and finally in the third it gives us $3 * 3 = 9$.

These numbers all differ from their respective answers by 1, and I thought that could be represented by adding a term to the above multiple, $(-1) ^ x$ where $x$ represents the boolean value of $a < b$.